Ingot and the mold and core structure for casting the same



Dec. 31, 1963 R. M. BRICK ETAL 3,116,121

INGOT AND THE MOLD AND CORE STRUCTURE FOR CASTING THE SAME Filed June20, 1960 5 Sheets-Sheet l 36 TIE-.1.

M 967 O ATTOZHEY$ Dec. 31, 14963 R. M. BRICK ETAL 3,116,121

INGOT AND THE MOLD AND CORE STRUCTURE FOR CASTING THE SAME Filed June20, 1960 5 Sheets-Sheet 2 TIEBS INVENTORS cmz-ns E. MMEQ, EOBEET M.BE\C.K.

' y EDWARD J. szwuue ATTC: 2U E (S Dec. 31, 1963 R. M. BRICK ETAL INGOTAND THE MOLD AND CORE STRUCTURE FOR CASTING THE SAME Filed June 20, 19605 Sheets-Sheet s INVENTORS 4o Cuans EMNEILJZQQEPI M. BZICL E; EDwAao.LEwuue- M QZ JA Ira 7 ATTORNEYS Dec. 31, 1963 R. M. BRICK ETAL3,116,121

INGOT AND THE MOLD AND CORE STRUCTURE FOR CASTING THE SAME W 2s & 26 iv/l 'll in K" i r M zg'ss 6% INVENTORS sq Cue-n: EMmaafloaam' M.B|z\c\ 8G7/ a @5 EDWARD JJZunme 1 BY 2 M, M, M y W, 82 15a. 85 K 52 ATTOEUEYSDec. 31, 1963 R. M. BRICK ETAL 3,116,121

INGOT AND THE MOLD AND CORE STRUCTURE FOR CASTING THE SAME Filed June20, 1960 5 Sheets-Sheet 5 S TIE-.15 4

E. TIE-I1 \IG)J 7G TIEIzlIEI Ike-.15 m

TIE- BU loq INVENTORS M, 915 V M ATTol2uEY United States Patent3,116,121 INGOT AND THE MOLD AND CORE STRUCTURE FUR CASTING THE SAMERobert Maynard Brick, Hinsdale, Curtis Eugene Maier, Riverside, andEdward Joseph Kipling, Flcssmoor, Ill., assigncrs to Continental CanCompany, Inc, New

York, NY, a corporation of New York Filed June 2t}, 1960, Ser. No.37,266 7 Claims. (Cl. 29-187) This invention relates to the art ofpreparing hollow ingots and laminate stock, and is particularlyconcerned with ingots and stock having longitudinal channels of closelydefined cross-sections.

It is known to prepare ingots having one or more such channels, and toreduce the thickness while extending the surface area, to form alaminate stock having a like number of discontinuities therein, andthereafter to open'or expand the stock by moving the laminations apartto form a tubular body with side walls comprised of the laminations andof integrating metal connecting the laminations at their longitudinaledges.

When the tubular body must have closely controlled internalcross-section, and the thicknessrcduction and a length-extension isbeing effected by rolling, there is a lateral spreading which variespredictably with the metal, the rolling schedule of temperature anddegree of reduction at each pass, and with the ingot shape. When hollowingots are thus rolled, the lateral spreading is not uniform for eachunit of width, nor for each unit of thickness: for example, with amulti-channel ingot of rectangular section and plane surfaces, thelateral spreading of a channel adjacent a lateral edge is greater thanthat for a channel nearer the center of width. 'Iherewith, for economy,it is desirable to provide the channel or channels during the casting ofthe ingot, and to have such channels originally of a size which canproduce the desired channel width in the laminate stock and the desiredcross-section in the opened tubular body.

An object of this invention is an apparatus for making hollow ingots, bywhich the dimensions of the channels can be closely controlled, by aprocedure of providing therein original channels of sizes proper underthe reducticn schedule to establish the predetermined final widths ofthe channels.

Another object is an appamatus for forming hollow ingcts by employmentof removable cores comprising relatively movable parts, whereby thechannel dimensions can be pre-set, and whereby the cores can be easilyremoved from the ingots without damage thereto.

Another object is an apparatus for casting hollow ingots in a mold oflimited size, from which the ingot being formed is withdrawn as portionsthereof cool to the solid state, and with cores which tnavel through themold with the molten and laterasolidified metal, and including thewithdrawal of the cores from the solidified ingots without damagethereto.

A further object is the preparation of hollow ingots having longitudinaledge and internal portions of metal softer than the cast ingot metalportions, and with longitudinal channels of predetermined dimensions inthe central portions.

With these and other objects in view, as will appear in the course ofthe following description and claims, illustrative embodiments of theinvention are shown in the accompanying drawings, in which:

FIGURE 1 is a conventionalized upright sectional view of a so-calleddirect-chill casting apparatus showing a practice under the invention;

FIGURE 2 is an end view of an ingot being cast in the mold, with coresand other parts in place;

3,115,121 Patented Dec. 31, 1963 FIGURE 3 is a horizontal view,essentially on line 33 of FIGURE 1;

FIGURE 4 is a penspective view of part of the mold platform, with partsof cores and other elements thereon;

FIGURE 5 is a perspective view of a core structure;

FIGURE 6 is an elevation of pants of a core structure, with the angle oftaper exaggerated;

FIGURE 7 is an end View, showing the relationship of the parts of a coremember having chisel-shaped edges;

FIGURE 8 is a corresponding view of a core member having rounded edges;

FIGURE 9 is a perspective view of a pair of spacer members;

FIGURES 10 land 11 show engagements of core members with spacers;

FIGURE 12 is a perspective view of part of an ingot made according tothis invention;

FIGURE 13 is a perspective view of a pant of a strip made by rolling theingot of FIGURE 12;

FIGURE 14 is an end view of part of the ingot of FIGURE 12, on a largerscale;

FIGURE 15 is an end view of part of the same ingot, on a still largerscale;

FIGURE 16 is a perspective view showing detachment of the edges of thestrip of FIGURE 13;

FIGURE 17 is a perspective view of a section cut from the strip ofFIGURE 16;

FIGURE 18 is a perspective view of a single blank;

FIGURE 19 is a perspective view of the same after opening;

FIGURE 20 is a perspective view showing the conformation of the URE 19.

In FIGURE 1, conventionalized parts are shown, including an ingotcasting mold 10 mounted on a deck or floor 11, above a pit into whichthe ingot is lowered during the course of its formation. The mold has aperipheral cooling chamber 12, with ducts 13 for supply and removal ofcooling fluid. A tundish structure 14, served by supply troughs 15, hasthe valved drop tubes 16 by which molten metal is delivered into thecasting mold. At the start of a casting operation, the lower end of themold lti is closed by a platform 17 connected to a piston ram structure18 which can be raised and lowered by a cylinder 19 accordingly as thedelivery or removal of pressure fluid to its ends is controlled by thevalve 20. The descending ingot B can be cooled by water jets from thenozzles 21.

According to this invention, one or more composite removable cores 25,FIGURES 1 to 4, are fixed and sealed in the platform 17 before the startof the metal pouring, and extend upwardly through the mold and betweenparts of the tundish structure 14. In a preferred form of practice,FIGURE 2, the individual core structures 25, of which four are shown,are located essentially at the median plane M between the ingot surfaceswhich are to be brought into reduction contact with the rolls: and pairsof abutting spacer members 26 are positioned between each two adjacentcore structures, with a single spacer member at the lateral edges of theoutermost core structures. The lateral margins 27 of the ingot need notbe cast with the central portion thereof, but may be provided bypro-formed edge pieces 28 which are originally connected to the platform17 and travel downward with the ingot. Such edge pieces 28 can have across-section of 1 to 2 inches along the median plane M, FIGURE 2, foringots 28 to 36 inches wide and 6 or 8 inches thick, dependent upon themetal being cast and the rolling schedule; and corresponding thicknessfor other ingot dimensions. The mold 10 can have inwardly projectingribs 29 which produce corresponding longitudinal grooves in the ingot,noting that pairs of such ribs can be employed of the opened blank,projecting fins of FIG- for guiding and aligning the edge pieces 28during their descent.

The core structures, spacers and edge pieces are assembled and attachedto the platform 17 as shown in FIG- URE 4. For this, the platform has anaperture and the core structures extend through the platform, so thatcleats 55 can be positioned below the platform wherewith only parts ofeach core structure having flat surfaces are located within the ingot,with the wider surfaces parallel to one another and providing continuousareas for defining the wider channel surfaces in the ingot. Spacers 26can be received also in the platform aperture. Normally, the edge pieces28 are heavier, and can descend in the mold by their own weights, or bythe downward pulls exerted upon the solidified ingot from the cores andspacers: pockets for aligning them may be provided in the platform, asin FIGURE 4. The core structures and spacers can be held by Wedges 31driven upward between a platform aperture wall and the structure orspacer. The end pieces 28 may be likewise secured. The platform aperturemay be made large enough for the widest spacers 26, when ingots are tobe made of differing dimensions with the single platform 17: wherewithdifferent numbers of spacers and cores can be assembled thereto, withwedges 31 of appropriate size to essentially fill the gaps. Fire claypacking 32 can be employed to fill any crevices.

The assembly can be guided and held, above the mold, as conventionallyshown in FIGURES 1 and 3. Rollers 33 engage the opposite faces of thecore structures and end pieces and hold them in alignment, beingrotatable on shafts carried by the rocker brackets 34 and having brakes35 pivoted on shafts 35a which restrict the rotation of the rollers, sothat a low tension is exerted along the core structures as the platformsinks: the brakes may be held engaged by springs 36. The rocker brackets34 are held engaged with the cores and end pieces by strong springs 36awhich permit minor movements under the forces exerted by thermalexpansion of the cores and end pieces. End guides comprising rollers 33aon springpressed rocker frames 34a act against the end pieces in theplane of the cores 25, and press them toward one another so that theseend pieces, the cores and the spacers 26 are held in abutment andaccurately guided for downward movement. The rocker frames 34, 34a arepivoted in fixed supports 37. Driven rollers 38 are preferably employedbelow the mold, for engaging the ingot B and exerting a downward effortupon it.

With the platform raised to close the mold bottom, and with the corestructures 25, the spacers 26, and the edge pieces 28 sealed in placethereon, the pouring of metal is begun. This metal solidifies within themold and upon the platform, and the level rises to near the top of themold, by control of the metal pouring as known in the art. The rollers38 are driven and valve 20 is operated, so that the platform descendswith the solidified lower part of the ingot B thereon. The pouring ofmetal and the descent of the platform are coordinated so that the levelof molten metal is kept essentially constant. In practice, the metalsolidifies as a film adjacent the cooled walls of the mold and againstthe core and other descending structures so that the zonal interfacebetween the liquid and the solidified ingot metal has a form asindicated by the lines 30, 30 in FIGURE 1. Therewith, the molten ingotmetal bonds or welds to the exposed surfaces of the spacers 26 and tothe end pieces 28: but does not bond to the core structures nor enterbetween the core members or between the spacers 26. In solidifying andcooling, the ingot metal, with the end pieces 28 and spacers 26integrated therewith, contracts and normally is free of the mold at thelower end thereof. When an ingot of the desired length has been formed,the platform 17 and the metal pouring are stopped: the molten metal isallowed to solidify, the ingot is withdrawn, new spacer and end piecesare introduced and the same or other cores positioned, and the pouring lof a new ingot begun with the platform 17 again raised into sealingposition.

The core structures 25 can be formed as in FIGURES 5, 6 and 7. The sidemembers 40 can have linear longitudinal outer edges of rounded form,FIGURE 8, but preferably are of chisel-shaped cross-section, FIGURE 7,formed by convergent surfaces leading to the extreme edges which can beblunted by a merging curvature of radius much smaller than the thicknessof the core; e.g., with a core thickness .of 0.125 inch, the includedangle at the chisel edge may be 10 to degrees, and the edge radius about1 inch. In practice, angles of 14 degrees and 28 degrees have been foundto yield essentially identical results. Angles of 10 to 60 degrees arepreferred for aluminum. The members 40 have inner edges which convergelongitudinally, FIGURE 6, for the pair of members, toward one end, e.g.,the lower end in the drawings. These inner edges have keyways '41illustrated as grooves of essentially triangular section with a 90degree root angle. The central member 42 has its edges of matingconvergent form, with a triangular sectional shape for each whichcorresponds to the keyway-s 41 and provides a key 43 accurately fittingthe keyway walls. Illustratively, for ingots up to 14 feet in length,each core member can be 16 feet long; the lateral members 40 can beabout 2 inches wide at one end and 1 /2 inches at the other: the centralmember 42 can be one inch wide at one end and two inches wide at theother: therewith, when the ends of the members are aligned, the over-allwidth is 5 inches at each end and along the entire length. Similarly,when a core width of, say, 6.12 inches is desired, the center member canlikewise be one inch wide at the lower end, and two inches wide at theupper end, and the side members can have dimensions of 2.66 inches atthe lower ends and 2.06 inches at the upper ends, for the same angle oftaper. Obviously, other coordinated dimensions can be selected,dependent upon the chosen taper angle and the desired core width.

Such chisel shapes facilitate the accurate assembly of the partspreliminary to pouring; and have a primary advantage in producing across-sectional shape of channel for receiving a liquefiable resist andwherewith the channel section changes during the early rolling passeswithout producing wrinkles or orange peel appearance of the surfaces ofsuch channels during the time of bringing the .opposed inner surfacestoward one another with a thin fihn of liquid resist between them.

The depth of the groove 60 in the spacer 26, FIGURE 9, determines theoverlap of the spacer metal onto the channel or discontinuity form bythe core assembly 25; and thus onto the resist or antiwelding materiallater introdueed into such channel, and ultimately the overlap of thespacer metal at the edge .of the resist residue in the rolled strip. Inpractice with liquefiable resists, the groove can be, for example, inchdeep with spacers 0.125 inch thick. Thus, FIGURE 10, when the corepieces 40, 42 are 0.125 inch thick, and the included edge angle is 90degrees, the angular edges fill the grooves. In FIGURE 11, where theincluded angle is 30 degrees and the core pieces are also illustratively0.125 inch thick, with the spacers 26 having a like thickness andgrooves for half this thickness, only parts of the angular edges arereceived in the respective grooves. In FIGURES '10 and 111, theweld-bonding of the cast metal .of the ingot B to the spacers 26 isindicated by the short hatching lines at the interfaces: and thenon-welding to the cores is shown by the absence of such hatching.

Such core members are made with surfaces of material to which the molteningot metal will not bond. For example, for ingots poured from aluminumor aluminum alloy, the bodies can be made of steel and given approximateshaping by machining. The keys and keyways are then accurately ground sothat the abutment wall surfaces are plane and smoothly finished, e.g.,to 10 microinches. These surfaces can be given a hard chromium plating.

The three members of a core structure are loosely assembled with thekeys and keyways engaged with one another, and then clamped into tightabutment: they are then surface-ground at the two sides to obtain thedesired thickness and to assure that such sides will form planes whilein service. These surfaces can also be given chrome plating, dueallowance therefor being made during the surface grinding. For example,each of the three members can be made 0.150 inch thick by machining andduring the formation of the keys and keyways; and then ground to 0.125inch thick while clamped together.

For the purpose of relative longitudinal location and securing of thecore members, the central member 42 is illustratively shown, FIGURE 6,as having a number of holes 45 spaced along its center of width; and theside members 40 have holes 46. Before assembly, it is preferred to applya lubricant for action between the key and keyway surfaces, which willbe effective after the heating by the ingot metal. For example, thewalls of the keyways 41 may be thinly coated with molybdenum disulfide.The core members are assembled by bringing them tightly together withthe keys in the keyways, and adjusting their relative longitudinalposition to obtain the desired width. Thus, with the above dimensions,the core structure will have a width of 5 or 6.12 inches when the endsare aligned as shown by the dash lines 47 in FIGURE 6 with the corewidth indicated by the dash lines 4% and the core member abutments bythe dash lines 4 9; noting that the langularity and spacing have beenexaggerated in FIGURE 6 for clearness. Upon shifting the central member42, e.g., upward in FIGURE 6 to the position shown by unbroken lines 50,and bringing the abutment between members at the unbroken lines 51, theover-all width between the edges of the side members is at lines 52,that is, the width has been decreased to the position shown by the dashlines 48 to that of the inbroken lines 52. By relative movement in theopposite direction, the width of the structure can be increased. Themembers can then be clamped in position, e.g., by cleats 55, FIGURES 4and 5, which have aligned holes 56 for receiving a pin or bolt 56a,which passes through a selected hole in the central member 4 2, andslits 57 for receiving bolts 57a which pass through the holes 46 of theside members 48. The cleats also may have holes 58 for clamping bolts53a which pass outside the core members. With dimensions .of the coremembers of 1 and 2.651 inches at the bottom with 2.151 and 2 inches atthe top, for a core 6.102 inches wide, when the lower ends are alignedas shown at the right in FIGURE 4 a longitudinal displacement of member42 upward from the dash line position, FIGURE 6, by one inch will givean over-all width of 6.097 inches, and a downward displacement will givea width of 6.107 inches: that is, by spacing the holes 45 ,one inchapart, the core structure can be varied in width by increments of 0.005inch.

lllustratively, if a can 4.06 inches in diameter is to be made, with arolling spread of 4 percent, the central core can be 6.122 inches wideat room temperature, and the successive lateral cores 6.102 and 6.082inches for a fivewide billet and strip. The five core widths then total30.490 inches. The spacers 26 can be 0.125 inch thick, with the grooves60 extending for half the thickness, with a total metal dimension, uponassembly, of 0.625 inch. The edge pieces 28 can each be 1%. inchesthick. The ingot thereby formed will have a total width, in the mold, inexcess of 34 inches: and upon cooling will have the channels essentiallyof the differentiated widths stated above.

The spacers 26 can be made, as in FIGURE 9, of rolled, extruded orforged stock of a metal compatible with the molten ingot metal: that is,the molten ingot metal can weld or bond to surfaces thereof so that thespacer becomes integrated into the ingot. With the preferredchisel-shaped edges on the core structures, an exposed face of eachspacer has a conforming longitudinal groove 63 so that the corestructures and spacers can be locked together, and are effective toprovide corresponding edges on the channels or discontinuities beingformed in the ingot. For aluminum or aluminum alloy poured ingot metal,the spacers 26 may be of wrought pure aluminum, which is softer thancommercial aluminum alloys and is advantageous when the poured metal isharder, to provide ductility along the edges of the channels during theopening operation. Pairs of these spacers are provided between adjacentcore structures, and one is provided between each outermost corestructure and the adjacent edge piece 28, as shown in FIG- URE 2. Beforeemployment, it is preferred to provide anti-welding coatings 61 on thebacks or flat abutment surfaces of the spacers: such may be a lightcoating of soot, e.g., by a smoky acetylene flame, or a bonded dressingof refractory oxide powder, or a thin silicone coating, for aluminumingots. Other surfaces of the spacers are preferably cleaned so that thepoured metal will bond easily and strongly thereto.

After the ingot B has been removed from the mold and platform, with thecore structures therein, these structures are removed. The cleats andthe bolts and pins therein can be removed before separating the ingotfrom the platform.

The small end of each center member 42 can be tapped, and the wide endpulled, so that this center member is pulled out from between the sidemembers 40, with its plane faces sliding along the inner surfaces of thechannel in the ingot. As it leaves, the compressive strains exerted fromsolidification shrinkage in the direction of the median plane M arerelieved, and the side members 4d can similarly be removed. Therewith,each core structure has establ shed a channel in the ingot of a sizedetermined by its own thickness and by the adjusted width between itslongitudinal edges; with parallel wider surfaces joined by theconvergent end sections.

Similar operations can be performed for ingots of other metals, withappropriate selection of materials. For copper, stainless steel can beused for the core members: for mild steels, titanium members are usable.With copper, the thin carbon films from a smoky flame can be used forthe anti-welding dressings: for steel, a flame sprayed refractory suchas alumina powder, is useful where carbidization is undesirable.

FIGURE 12 shows an ingot formed with cores of the type in FIGURE 7, therelative width dimensions being exaggerated for clearness. This ingot Bhas five core channels aligned along the median plane M of itsthickness. The central channel is the widest, being 6.122 inches in anillustrative example above: the next outwar channels 71 are each 6.102inches wide; and the laterally outermost channels 72 are each 6.082inches Wide.

The cast metal has bonded with the spacers and the edge or end pieces;so that only the inter-spacer antiwelding layers 61 are present at theingot ends. The ingot can be formed with the longitudinal externalgrooves '73 which can he of v section and arranged in pairs at theregions of the layers 6.1: such can be produced by the ribs 2%, FlIGURE2, and then dressed to the desired final size and shape; and preferablyreceive on one or both walls of each groove a coating of anti-wcldingmaterial.

One end of such an ingot can then be closed by wedges and welding, and aliquefiable resist introduced. For aluminum ingots, suitable resistmaterials are organic substances such as polysiloxanes, polyvalent metalstearates such as the ferric or aluminum soaps, epoxy resins,hydrocarbon polymers such as polyethylene and polypropylene. Suchorganic materials have been found to endure temperatures of 900 to 1,000degrees F. without losing ability to prevent welding of the metal whenemployed as set out herein. Such materials can liquefy below suchtemperatures but maintain the desired antiwelding property when air isexcluded. The ingot can be heated for homogenization, the resistintroduced, and the hot rolling begun at once so that the How of themetal with closure of the core channel walls upon the resist quicklyeffects expulsion of air and prevents its re-entry: or the ingot may bebrought to a temperature of 300 to 500 degrees, at which the resistliquefies, the resist introduced and the other ingot end sealed, and theingot raised to the hot-rolling temperature.

Refractory resist materials, such as particles of alumina, zirconia,silica and silicates, talc, and graphite, in sizes of a few micronsdownward, can be introduced into the channels of ingots formed in thepresent fashion, for example, by vibrating the ingot while the powder isbeing introduced into the channels, and thereby attaining asubstantially uniform packing with uniform density of the resist. Theingot is then raised to the hot-rolling temperature.

The ingot is then hot-rolled. During the early breakdown passes, thechannel surfaces approach one another, without the formation of internalwrinkles when the channel has been formed from cores as in FIGURE 7.Thus, an ingot 8 to 12 inches thick can be reduced to a slab or billet 4to 6 inches thick, having the longitudinal core channels therein andeach filled with resist material from edge to edge and end to end. Thebillet can be reheated to 900 degrees, for an aluminum or aluminum alloybillet; and further hot-rolled to a hot band 0.090 to 0.150 inch thick,which can be heat-treated, and then cold-rolled to the desired finalgage, e.g., 0.010 to 0.020 inch, with intermediate annealings ifdesired. For examples, with standard 3003 or 5052 aluminum alloys, thefinal intermediate annealing during cold-rolling can be performed at athickness at which the finished strip will have the hardness desired,such as quarter-hard, half-hard, or fullhard. Some alloys canadvantageously be heat-treated after cold-rolling to final gage. Forexample, 5052 aluminum alloy may be heated for l to 4 hours at 350 to500 degrees (F. to relieve stresses: and 6061 aluminum alloy may beheated for an hour at 980 degrees F. to remove work hardening effectsand cause precipitation components such as magnesium silicide tore-dissol-ve; with quenching in cold water so that age-hardening canlater occur at room temperature or be accelerated by heating to 300 to400 degrees F. to attain the hardest temper effect. In general, thestrip can be annealed and quenched as a coil: it is prefered to pass thestrip through a rollerleveler after quenching, to eliminate warpageeffects which have arisen.

During the course of the rolling, there is usually a lateral spreadingof the ingot by /2 to percent or more in width. The greater the degreeof reduction per pass, the greater the spreading during such pass. Thespreading with rectangular billets having resist-filled internalchannels is not uniform for like units of width: in general, thechannels at the center of width spread less than those closer to thelateral edges. Here, also, with greater reduction per pass, thedifferential spread of the channels is greater. This can be compensatedby the differentiated width of the resist-filled channels, and by thepresence and tilting of the longitudinal external grooves.

Further, the surfaces 75, FIGURE 12, originally in contact with therolls, and later the upper and lower surfaces of the partly rolledbillet, have essentially no lateral spread, but the spreading effectoccurs between such surfaces, for example, adjacent the median plane M.This is compensated by the tilting of the grooves, and by the lateraldisplacement of the roots of these grooves relative to the adjacentspacer pieces.

It is desirable, when tubes of specified internal size are to be thefinal product, that the widths of the resist residues 76, FIGURE 13,should be the same. In practice, during rolling of a rectangular billethaving originally channels 71 of the same width, the channels ad- 8jacent the longitudinal edges are Wider than those at the center.

Under the practice of this invention, the channels 71 are initially ofdifferentiated widths, so that the rolled strip S, FIGURE 13, has theresist residues 76 of the same widths by reason of the compensation dueto lateral spreading, and the residues '77 of the coatings applied inthe grooves 73 extend at right angles from the rolled surfaces andnormally are invisible in the rolled strip, but reveal themselves whenthe strip is bent about longitudinal axes.

It is preferred to shape and locate the external longitudinal grooves 73of FIGURE 12 as shown by FIGURE 14, in which one lateral half of afive-channel ingot B is shown at theleft of the upright central plane C.The ingot is symmetrical about the median plane M. The spacers 25 areoutlined, with hatched lines to indicate that they have becomeintegrated into the billet. The successive external grooves 75a, 75b,75c from the central plane are shown as having successively greatertilts; that is, the bisector planes 30a, 30b, c, have successivelygreater angles from the upright planes 81a, 81b, 81c which pass throughthe roots of the respective pairs of grooves. Such grooves may have rootangles of 10 to 70 degrees: the depths of the grooves, from therespective ingot surfaces 82 such that the total of the two grooves andthe upright dimension of the interspacer parting material 61 does notexceed half of the total ingot thickness between the surfaces 82.

It is also preferred, noting FIGURE 14, so to locate the grooves 75 thatthe lateral spreading adjacent the median plane M, as compared to theusual lack of spreading at the surfaces 82 Which are in contact with therolls during rolling, is also compensated. Thus, the upright plane 81adefined by the roots of the grooves 75a passes laterally outside thecoating 61 of the associated spacers 26 by a small distance,corresponding to the limited lateral spreading of the channel 70 duringrolling: while the planes 81b defined by the roots of the grooves 75band the planes 81c defined by the roots of the grooves 75c are atsuccessively greater distances from the respective coatings 61.Therewith, with the selected rolling schedule, the differential lateralspreading of the core channels 70, 71, 72 during rolling brings thegroove roots and the coatings 61 into alignment at the end of rolling.

Coatings 85, FIGURE 15, of anti-welding material such as a polysiloxanegrease, a bonded inorganic powder, or soot, is applied to one or bothwalls of each groove, to prevent later welding between the Wall surfacesand to establish longitudinal weakening or notching effects in therolled strip.

The effects during rolling are illustrated in FIGURE 15. During theearly rolling passes, there is a minor lateral flow of metal beneath butnear the surfaces 82, so that the grooves become closed, as shown by theshort arrows $6. Therewith, the ingot is reduced in thickness toestablish the surfaces 87, and the anti-'weld residues of coatings 85have become films 88 extending from these surfaces: noting that themetal flow has not yet shifted the films so that the films of a pair ofgrooves lie in a common upright plane, but are still relatively tilted.Therewith the thickness of the channels 70, '71, 72 and the spacers 26of FIGURE 14 are likewise reduced as shown by the dotted lines in FIGURE15, noting that such reductions are usually not linearly proportionateto the total thickness reduction from lines 32-432 to lines 87-87.During the continuance of rolling, the metal between the inner edges ofthe films 88 spreads laterally away from the center plane C, andtherewith the coating 61 moves outward. At the end of the rollingschedule, the films 88 have become erect, and lie in a plane whichpasses through the respective coating 61: and there are three weaknessareas at each such plane, two being provided by the films 88 whichextend from the outer surfaces, and the third by the respective coating61. The

thickness of the ingot is successively reduced by the rolling, until thestrip of FIGURE 13 is produced; and therewith, the dimensions of thefilms 88 and coatings 61 are likewise reduced in essentially the sameproportion. When the resist material in the core channels 70, 7'1, 72 isliquid during the hot rolling, the thicknes of these channels is reducedduring the course of the rolling, usually with expulsion of some of theresist material at the initial hotpass, so that the final thickness ofthe core channel resist residue may be a few ten-thousandths of an inchor less. For example, if the strip of FIGURE 13 is 0.020 inch thick, thecombined dimensions of the Weakenings can occupy 0.008 or 0.009 inch,and the remainder of the thickness is composed of rolled metal. Thegreater travel of metal, in the lateral spreading, at points nearer themedian plane M than the inner edges of the films 88 is indicated by thelonger arrows 8?.

With ingots shaped as in FIGURES 14 and 15, during early stages of therolling between surfaces 82, the channel 70 at the center plane C isbroadened less than the lateral channels 71 and 72. The flow of metallaterally as at 86 to close the lateral grooves 75a, 75b, and 75::establishes some compensation, so that this factor, combined with thedifferentiated widths of the channels 70, 7'1 and 72, has the resultthat with a given rolling schedule, the channels will have uniformwidths at the end of rollmg.

The grooves 75c nearest the margins of the billet provide alignedresidues which are at essentially uniform spacing from the edges of theresidues 76 in the outermost channels 72. During the rolling, the stripmay receive camber, that is, its lateral edges are curved rather thanstraight lines. During the coiling of the strip when rolled to finalthickness, the marginal portions 94), FIG- URE 16, may be torn away,with the severance following the lines of the residues 77, so that theedges of the residual central portion of the strip now lie atessentially uniform distances from the edges of the outermost channelresist residues 76 and can be employed as reference lines in cutting thestrip into sheets along lines at right angles to these reference edges,even though camber is present.

Thus, in FIGURE 17, the rolled strip S, with five channel resistresidues extending along its length, may be severed at lines 91 to formpanels or sections P of multihigh, m-ulti-wide individual blanks, whichcan receive lithographic coating, embossing, and other treatments asmultiple units. Such sheets can then be separated into individualblanks, by bending the sections about longitudinal axes, that is, axesparallel to the weakenings 77, thereby over-stressing the .metal alongthe planes of the resist residues 88, 61, and causing the sheet to breakalong these planes, without intrusion of the break into the channelresist residue regions. In the original ingot of 8 to 12 inch thickness,the edges of the cores may be spaced /8 inch from one another: but whensuch an ingot is rolled to a strip 0.20 inch thick, the distance betweena pair of surface resist residues 88 is far less than the spacingbetween the cores. Such a piece may have the length of one or moreindividual blanks, and it may now be trimmed and severed as desired, toprovide a single blank 1%, FIGURE 18.

An individual blank 100, FIGURE 18, may be opened or expanded, as by amandrel 191, into a desired tubular section, FIGURE 19. Therewith, whena ductile metal has been employed for the spacers, the bending at theedges of the channel resist residue 7 6 occurs in such metal asindicated by the dotted limit lines 101:: for the portions 102 of thesoft metal: and the lamination portions 193, 104 of harder metal arebent apart to curves of greater radii. Therewith, the outwardlyprojecting fins 105 are of soft metal, of double the thickness of thelaminations 103, 104, and present re-entrant angles 1% at the innersurface. After trimming the fins, if desired, they may be reduced indistance of projection as shown in FIGURE 20 by the illustrative use ofa hammer tool 108, while the expanded tube is supported internally by ananvil 109 of appropriate section, so that the inner and out-er surfacesof the tube are smoothed, with essential disappearance of the re-entrantangle, as shown in FIGURE 20.

The illustrative practices are not restrictive, and the invention can bepracticed in other ways within the scope of the appended claims.

What is claimed is:

1. An ingot competent of rolling to produce a laminate strip having amultiplicity of longitudinally extending non-welded internal regions ofuniform width and spaced laterally from one another and from the edgesof the strip, comprising a metal body having essentially parallelexternal surfaces to be engaged by the reduction rolls, and havingbetween said surfaces and spaced from one another and the lateral edgesof the body a multiplicity of hollow longitudinally extending internalchannels located substantially in a plane, the channels havingsuccessively lesser widths from the center of width of the body towardits lateral edges whereby differential lateral spreading of the channelsduring rolling will bring the channels to a uniform width in producingthe strip, the metal between each two adjacent channels havingmetallurgically a wrought structure and integratedly bonded to the castmetal structure of other parts of the ingot.

2. An ingot as in claim 1, in which the metal between each two adjacentchannels is in two parts separated by a layer of anti-welding materialextending across said plane and terminating in spaced relation to saidparallel external surfaces.

3. A mold and core structure for casting ingots having a multiplicity ofhollow internal longitudinal channels therein, said channels havingdiffering widths, comprising a mold body having a mold cavity therein, aplurality of core structures each having side and center members withinterengaging parts at their abutting edges, the center member beingtapered at its said edges from end to end of its mold-received portionand the side members each having the abutting edges thereof taperedoppositely to mate with the taper of the center member, said membershaving mating ribs and grooves along their abutting edges and beingadjustable longitudinally relative to one another, each said corestructure presenting surfaces extending across the central and sidemembers thereof for forming the surfaces of a channel in the ingot andmeans for holding the members in the mold cavity and in edgeabuttingrelation whereby the distance between the outer edges of the sidemembers and thereby of the respective widths of the channels beingformed is determined by the prevailing relative longitudinal positionsof the members and the mating ribs and grooves maintain the ingot-metalexposed surfaces in alinement.

4. An apparatus for making ingots having a plurality of hollow internallongitudinal fiat channels extending from end to end thereof, saidchannels being of controllably differing individual widths between theirlateral edges, which comprises a mold member having an upright moldcavity extending therethrough, with the sides of the horizontalcross-section of the mold cavity closer together than the ends of thesaid cross-section of said cavity, a plurality of core structures eachhaving abutting and inter-engaged side and center members of matinginverse edge tapers and having surfaces resistant to bonding by themolten ingot metal, said side members presenting lateral edges forforming the said lateral edges of the respective channel, said membersbeing located in the said mold cavity in a row essentially parallel tothe sides thereof and being longer than the ingot to be made so thatthey extend below the bottom of the ingot mold and above its top, meansfor closing the bottom of the mold member and having apertures throughwhich the core structures can be introduced, holding means located belowthe bottom of the mold member and including individual parts forengaging and supporting the side and center members of the corestructures with the said members of each core structure in said abuttingand interengaged condition at the lower end of the mold member, saidparts being constructed and arranged for holding the center member of acore structure at a different height than the side members thereof sothat the lateral edges of the said side members can be secured by saidparts at the distance proper for the selected controlled width of therespective channel, and means located above the top of the mold memberfor holding the said side and center members of the core structures insaid abutting and interengaged condition at the top of the mold and formaintaining a selected spacing between adjacent core structures.

5. An apparatus as in claim 4, including means for withdrawing said moldbottom closing means and said individual core member holding partsdownward at a concurrent rate.

6. An apparatus as in claim 4, in which the mold bottom closing meanshas openings located between the said apertures for the core structuresfor the passage of preformed spacer pieces to be integrated into theingot being formed, in which said holding means include parts forholding such spacer pieces between and in contact with and immovablerelative to said core structures, and in which said holding meanslocated above the mold member includes parts for holding said spacerpieces and core members in abutment with one another.

7. An apparatus as in claim 4, in which the members of each corestructure are of like thickness, and in which the said holding meanslocated above the mold member includes guides engaged with the membersof each core structure to hold their engaged surfaces in parallelplanes, with the core structures essentially midway between the sides ofthe horizontal cross-section of the mold cavity.

References Cited in the file of this patent UNITED STATES PATENTS1,984,186 Haber Dec. 11, 1934 2,286,994 Nocar June 16, 1942 2,818,618Winship et a1 Jan. 7, 1958 2,845,695 Grenell Aug. 5, 1958 2,950,512Wilkins Aug. 30, 1960 2,957,234 Valyi Oct. 25, 1960 2,986,810 Brick 1June 6, 1961 3,016,587 Brick Jan. 16, 1962

1. AN INGOT COMPETENT OF ROLLING TO PRODUCE A LAMINATE STRIP HAVING AMULTIPLICITY OF LONGITUDINALLY EXTENDING NON-WELDED INTERNAL RGIONS OFUNIFORM WIDTH AND SPACED LATERALLY FROM ONE ANOTHER AND FROM THE EDGESOF THE STRIP, COMPRISING A METAL BODY HAVING ESSENTIALLY PARALLELEXTERNAL SURFACES TO BE ENGAGED BY THE REDUCTION ROLLS, AND HAVINGBETWEEN SAID SURFACES AND SPACED FROM ONE ANOTHER AND THE LATERAL EDGESOF THE BODY A MULTIPLICITY OF HOLLOW LONGITUDINALLY EXTENDING INTERNALCHANNELS LOCATED SUBSTANTIALLY IN A PLANE, THE CHANNELS HAVINGSUCCESSIVELY LESSER WIDTHS FROM THE CENTER OF WIDTH OF THE BODY TOWARDITS LATERAL EDGES WHEREBY DIFFERENTIAL LATERAL SPREADING OF THE CHANNELSDURING ROLLING WILL BRING THE CHANNELS TO A UNIFORM WIDTH IN PRODUCINGTHE STRIP, THE METAL BETWEEN EACH TWO ADJACENT CHANNELS HAVINGMETALLURGICALLY A WROUGHT STRUCTURE AND INTEGRATEDLY BONDED TO THE CASTMETAL STRUCTURE OF OTHER PARTS OF INGOT.
 3. A MOLD AND CORE STRUCTUREFOR CASTING INGOTS HAVING A MULTIPLICITY OF HOLLOW INTERNAL LONGITUDINALCHANNELS THEREIN, SAID CHANNELS HAVING DIFFERING WIDTHS, COMPRISING AMOLD BODY HAVING A MOLD CAVITY THERIN, A PLURALITY OF CORE STRUCTURESEACH HAVING SIDE AND CENTER MEMBERS WITH INTERENGAGING PARTS AT THEIRABUTTING EDGES, THE CENTER MEMBER BEING TAPERED AT ITS SAID EDGES FROMEND TO END OF IS MOLD-RECEIVED PORTION AND THE SIDE MEMBERS EACH HAVINGABUTTING EDGES THEREOF TAPERED OPPOSITELY TO MATE WITH THE TAPER OF THECENTER MEMBER, SAID MEMBERS HAVING MATING RIBS AND GROOVES ALONG THEIRABUTTING EDGES AND BEING ADJUSTABLE LONGITUDINALLY RELATIVE TO ONEANOTHER, EACH SAID CORE STRUCTURE PRESENTING SURFACES EXTENDING ACROSSTHE CENTRAL AND SIDE MEMBERS THEREOF FOR FORMING THE SURFACES OF ACHANNEL IN THE INGOT AND MEANS FOR HOLDING THE MEMBERS IN THE MOLDCAVITY AND IN EDGEABUTTING RELATION WHEREBY THE DISTANCE BETWEEN THEOUTER EDGES OF THE SIDE MEMBERS AND THEREBY OF THE RESPECTIVE WIDTHS OFTHE CHANNELS BEING FORMED IS DETERMINED BY THE PREVAILING RELATIVELONGITUDINAL POSITIONS OF THE MEMBERS AND THE MATING RIBS AND GROOVESMAINTAIN THE INGOT-METAL EXPOSED SURFACES IN ALINEMENT.